Automatic ice cube making apparatus



v Nov. 3, 1964 A. E. LlT'rLE 3,154,929

AUTOMATIC ICE CUBE MAKING APPARATUS Filed June 5, 1961 3 Sheets-Sheet 1 E6: l 75 lil! Nov. 3, 1964 A. E. LITTLE AUTOMATIC ICE CUBE MAKING APPARATUS 3 Sheets-Sheet 2 Filed June 5, 1961 A. E. LITTLE AUTOMATIC ICE CUBE MAKING APPARATUS Nov 32 Filed June 5,v 1961 3 Sheetls-Sheet 3 v ZNVENTOQ United States Patent O 3,154,929 AUTOMATC FCE CUBE MAKING APPARATUS Alfred E. Little, Glendale, Mo., assigner, by mesne assignments, to White-Rodgers Company, a corporation of Missouri Filed `lune 5, 196i, Ser. No. M4355 l2 Claims. (El. 62-137) This invention relates :to apparatus for automatically forming and ejecting small ice cubes and particularly to apparatus of this type adapted rto be installed in the freezing compartments of household refrigerators.

Primarily, the object of the invention is :to provide a generally new and fullly automatic apparatus of this type which is particularly simple and economical in construction `and reliable in operation.

A further object is the provision of an automatic ice cube-making apparatus having an inexpensive, conveniently replaceable, multiple cavity, cube freezing tray.

A further object is the provision of an automatic ice cube making apparatus in which positive and reliable ejection of the cubes from the cube freezing tray is achieved with relatively small force due to the shape of the freezing tray and the manner of application of the force to the cubes to be ejected.

A further object is the provision of a multiple cavity cube freezing tray constructed of a synthetic plastic material through which heat is conducted relatively slowly, but to the :surface of which the adherence of ice is relatively low, and a cube ejection element having a high rate of heat conductivity, such as aluminum, and having sufficient mass extending into the tray cavities and exteriorly thereof to appreciably accelerate the freezing of water in the tray cavities.

A further object of the invention is to provide an automatic ice cube making appanatus in which ice cubes are ejected from a multiple cavity tray by applying force to the cubes in a manner to squeeze them from the tray cavities in a manner to apply force normal and parallel to the surfaces of the ice cubes rather than pry them out or 'sweep them out.

Other objects and advantages of the invention will appear from the following description when read in connection with the accompanying drawings.

In .the drawings:

` FIG. l is a top plan view of a device for making ice cubes which is constructed in accordance with the present invention;

FIG. 2 is a front elevation of the device FIG. 1;

FlG. 3 is 1a left end elevational view of the device shown in FIGS. l and 2;

FG. tis a fragmentary cross-sectional view taken on line d-d of FIG., 2, showing the cube ejecting element in a retracted position;

FIG. 5 is a similar cross-sectional view taken on line 4-4i of FIG. 2, showing the cube ejecting element in an intermediate position of its cube ejecting stroke;

FIG. 6 is a fragmentary chess-sectional view of the sensing element taken on line 6 6 of FIG. 2;

FlG. 7 is a fragmentary elevational View showing the cam-operated switches for controlling the operation of the cube ejection means, the sensing device heater, and the cavity filling means;

FIG. 8 is a sectional view of the sensing element taken on line 8 8 of FIG. 6; and v FIG. 9 is a diagram of the circuits-controlling the electrically operated device.

Referring to the drawings in more detail, numeral 1t) generallyindicates an integrally cast aluminum frame having a horizontal base 12, a vertical back plate 14 provided with screw holes Mia therein for mounting the shown in 3,l54,929 Patented Nov. 3, 1964 device on the freezing compartment wall of a domestic refrigerator, a transverse, vertical, motor mounting plate ld, and a longitudinal, front tray mounting plate 1S which extends upward at an acute angle from the base l2. Attached to the front plate 18 is a multi-cavity freezing tray generally indicated at 2Q.

The tray Ztl is preferably a unitary structure formed by molding a suitable synthetic plastic material and comprising ice forming cavities 22, a flange 24 extending along the front and sides thereof, a curved attaching iange 26 extending along the rear thereof, and a deflecting baffle Ztl extending along the rear and sides thereof. rThe tray also includes a hollow, cylindrical boss 3i), preferably formed as an integral part of the tray, adapted to receive a sensing element calibrated to detect cornplete solidiiication of water in the tray cavities. The boss 3@ extends downward from the bottom wall of one of the `tray cavities and has a cylindrical recess 32 which receives .a cylindrical sensing unit generally indicated at 34.

Referring to FIG. 6, sensing element 34 comprises an open-ended, hollow, cylindrical casing 36 of dielectric material having a short square-shouldered counterbore 3&2 at the upper end thereof which receives the periphery of a circular-formed bimetal disc dil. A circular clip member 42 having a radially extending flange portion i4 which overlies the periphery of the disc 4t) and an axially extending cylindrical portion 46 which is formed at its end over a shoulder i7 provided on the casing 36 retains the bimetal disc 40 in the counterbore 38. The formed bimetal disc itl is shown in FlG. 6 in the shape which it assumes at temperatures above those which would result in the complete solidification of water in the tray cavity immediately above. When the temperature drops to that which would result in complete solidication, the disc snaps from its indicated upwardly curved shape through a planar shape to a downwardly curved shape and in doing so engages the upper end of a switch operating rod i8 below and moves it downward.

The switch operating rod il passes downwardly through a central opening in carbon resistance heating disc and an insulating disc 52, and between the inner ends of a pair of stationary contact members 54, and then into a guide bore Se formed in an insulating plug 5S. The operating rod ed carries a conductor disc 6i? which, when the rod is moved downward, bridges the stationary contact member 54 to complete a conductive path between a pair of terminal pins d2 which are attached to contact members 5d and which project downwardly through plug 525 and extend exteriorly thereof. A second pair of terminal pins 64 extend upwardly through plug 53, through insulating disc 52, and are electrically and mechanically connected iat their upper ends (not shown) to the carbon disc 5h. A return spring 66 in guide bore 5a biases the switch operating rod 4S upward toward an open circuit position.

The sensing element assembly 42 is entered into the bore 32 in slip fit relationship and retained therein by a lower cover member o8, which is preferably attached to the lower end of the boss 3@ by pinning and gluing so as to hermetically seal the sensing device within the cylindrical bore 32. The holes in cover 63 through which the projecting terminal pins 62 and 64 pass are also suitably sealed. The contour of the central portion of the bottom of the cylindrical bore 32 is shaped so as to conform with the convex upper surface of disc-4;@ so that, when the disc is in the position shown, substantially its whole area will be in heat-conducting relationship with the wall portion 7d which separates it from the cavity 22 immediately above.

Referring to FIG. 2, it will be noted that the cube forming cavities comprise a plurality of articulated ice cube forming receptacles, each having four separate walls extending the greater portion of their water-retaining depth, thereby to expedite freezing. Referring to FIGS. 2 and 4, it will be seen that the side walls 72 of each cavity, as well as the front wall 74 and rear wall 76, diverge upwardly with respect to each other and that the bottom wall of each cavity is formed by a smooth inward curving of the lower portion of front wall 74 to a point of intersection with rear wall 76. This particular shape greatly facilitates ejection of the ice cubes in the manner in which this is accomplished in the present invention.

The straight rear wall 76 of each cavity lies flat against the face of the rigid front plate 18 of the cast aluminum frame, whereby the entire rear cavity wall is in good heat transfer rleationship with the considerable mass of high heat conductive material comprising the cast frame. The upper edge of the front frame plate 1S is provided with a short, rearwardly extending, horizontal lip 7S over which the curved attaching flange ofthe tray is hooked, thereby providing a simple, readily detachable means for securely mounting the cube freezing tray on the frame. A single locking screw Sti at each end of the tray, see FlGS. 1 and 3, prevents inadvertent'lifting of the tray from the frame wall 18. The screws are spaced somewhat forward of the described attaching means and enter forwardly extending, horizontal frame lugs 82 formed at the upper edge of a pair of forwardly extending vertical frame lugs 84 located at each end of the front frame plate.

The cube ejection means comprises a longitudinal plate member 36 having downwardly extending articulated blades 37 which extend to the bottom of each cavity. The blades 87 are shaped to conform with the side walls and the bottoms of the cavities, and plate 86 is preferably constructed from extruded aluminum stock. Plate 86 is constructed of sufficiently thick stock as to insure against permanent distortion under the potential stress in operation and because of its mass and surface area in contact with liquid in the freezing cavities assists appreciably in conducting heat from the liquid to the ambient air. The plate 86 is rigidly attached at its ends to the upper ends of a pair of pivoted arms 8S, and arms 88 are pivotally mounted at their lower ends on pivots S9 mounted in forwardly extending frame lugs S4. The pivot points of arms 88 are so located that the lower edges of the articulated blades 87 pivot substantially at the intersection of the curved front wall 74 and the rear wall 7o of the cavities as arms 33 are oscillated on their pivots.

Mounted rearwardly of the freezing tray on the forwardly extending vertical frame plate liti is a geared driving motor assembly generally indicated at 9i). Motor 90 has a driving shaft 92 to one end of which is rigidly attached a crank 9d. A connecting rod 96 pivotally connected at one end on a pivot 93 to the crank 9d, and at its other end to the ejector plate 86 at an intermediate point thereon by a pivot Vlltltl, effects the'oscillation of Vplate 86 as the motor drive shaft.92 rotates. Mounted on the other end of driving shaft 92 is a pair of switch operating cams 102 and 104 which respectively actuate a double-,throw f switch 1% and a single-throw normally open switch 10S,

See FIGS. l and 9L Water is delivered to ythe freezing tray through a suit,- able conduit l1@ under the control of a suitable electromagnetically operated valve lf2, see FIG. 9. The conduit il@ is preferably provided at its 'discharge end with divided, oppositely directed, discharge openings 114,' arrangedto discharge in opposite'di'rections along the horizontal portion ofrear curved ange-Zo of the lfreezing tray.l j

FG; 9 schematically" shows the electrically operated components ofthe device, and circuits therefor, and include-s as primary elements: sensing switch contacts 54E-6i), the double-throw, Vcam-operated switch litio, Ythe driving motor 9d, the carbon resistor 5@ of thefsensingdevice, the normally open, ,single-throw, cam-operated switch w8, the electromagnetically operated valve 112, and power source terminal posts lid-M8. The driving motor 90 and carbon resistance heater 50 are initially energized upon closure of sensing switch contacts 54-60 through the doubleJthrow switch idd when in its indicated solid line position. Shortly after the starting of motor 90, the motor driven cam 162 throws switch lila to its dotted line position and the motor 9i) and carbon resistance heater 5t) ly. The motor driven cam 104- is angularly positioned on vtaire-off shaft 92 soas to effect the closing of switch N8 and therefore the energization and opening of electromagnetic water valve 112 during a predetermined portion of the second or last 180 angular degrees of rotation of the motor shaft 92. While any suitable motor means for rotating shaft M2 may be employed, I prefer presently to use an inexpensive motor having a nominal rotational speed in the order of 3000 r.p.m. with a gear reduction assembly which results in a take-off shaft speed of one r.p.rn. It will be appreciated that'with a gear reduction in the order of 3G60 to 1 any timing variation at the takeoff shaft due to normal variations in nominal motor speed would be diminished to a negligible amount. The traylling time, during which the lobe on cam 104 maintains switch 193 closed to effect an open position of water valve H2, may, therefore, be readily determined with suiiicient accuracy. lt will be understood that .suitable,.inexpensive, resilient, constant iiow orifices are commercially available which operate automatically to maintain a reasonably constant flow under variations in water supply line pressure, and applicant contemplates the use of such device.

In Operation vroperation' when complete solidiication ofthe water in the tray cavities occurs, bimetal disc 4@ will snap from its indicated Yshape in YFIG. `6 to a downward curvature, thereby depressing 'rod 43 land effecting` the bridging of contacts 54 by conductor disc 6ft. The himetal disc 4t) is, of course, constructed and formed so asrto respond to some predetermined temperature, somewhat below 32or Fahrenheit, which reects la. condition ofcomplete y -solidication' in the tray cavity above. Y

The bridging of contacts 54 initiates energization of the driving motor 9d and the parallel connected carbon resistance heater Si) through switch 106m its indicated solid line position. Very shortly after the motor starts,

motor driven cam 102 throws switch 106 toits dotted line position, thereby shunting sensing switch contacts Sdfotl so that the motoris now energized tofcomplete one revolution of take-off Vshaft 92 independently of the sensing switch. When the'motor shaft 92 has completed one revolution switch lilo again drops baclctojits solid llinie position, but by this time.(in the orderof one minute), Y the carbon resistance heater Stil has heated adjacent bi-r metal disc ttl'suiiciently to cause Yitto'snap back to its upwardly curved position and permit contacts Sd-tl to separate so that the motor is de-.energized Vafter the completion of. one revolution'of the take-offshaft.

crank 94 is substantially on dead center with respect to its operative connection with plate 86 so that, initially, a gradual acceleration of the ejector plate swing occurs at the constant speed rotation of the take-olf shaft. Thus, the maximum application of force is lapplied relatively slowly at the start of motor operation. The action of the ejector blade upon the ice cubes is a scissors-like action in which substantial force is applied both normal to and parallel with the rear, front, :and bottom surfaces of the cubes and substantially parallel with the sides of the cubes. The lower edges of the articulated blades of the ejector plate bear against the rear walls of the cavities 'as force is applied to the upper edge of the plate, and inasmuch as the rear cavity walls are backed up by the rigid front frame plate l, any rearward shifting of the pivot point is precluded. The arms 8S, of course, prevent any climbing or rising of the ejector plate when force is applied.

The ice cubes release upon initial slight movement of the ejector plate and are then ejected by continued squeezing action at an accelerated rate ias the crank 94 appreaches its 90 position. It is important that the cubes are ejected as soon as possible after they are released, or cracked loose, in order to preclude a refrozen adherence of the cube to the aluminum ejector plate. This may occur if the movement of the plate is too slow after ejection because of the melting of a very thin layer on the rear cube surface due to pressure on the plate against the cube. By the time the crank 94 has traveled 90 or slightly more, the ice cubes, due to their shape, fall over the front edge of the tray to be collected in any suitable receptacle placed below. The ejector plate continues to swing forward until the crank 94 has traveled 180, whereafter it returns as the crank continues through its return throw.

During the 180 return throw of the crank, the lobe on motor driven cam lddactuates switch lliltl to a closed position for `a predetermined interval in the order of fifteen or twenty seconds (90 to 120 angular degrees). The switch 103 opens and valve M2 closes somewhat before the ejector blade returns to its start position.

While the use of freezing trays constructed of other materials than a suitable synthetic plastic material, for example, aluminum, would function quite satisfactorily in applicants device and is contemplated, applicant considers that there are at least two important advantages in constructing the trays by the molding of a suitable synthetic plastic. One of these advantages is that it requires considerably less force to release frozen cubes from the surface of 'a synthetic plastic material than from metals, and the other advantage is that a plastic freezing tray constructed by a simple molding process and including a hermetically sealed sensing element, as disclosed by applicant, can be produced Iat `a considerably lower cost than a metal tray and would permit occasional replacement at a quite reasonable cost. Replacement of cube freezing trays may be desirable for other reasons than breakage or normal deterioration; accumulations of discoloring precipitates rotten render it desirable to re place the tray.

The foregoing description and drawings `are intended to be illustrative and not limiting, the scope of the invena tion being set forth in the .appended claims.

l claim:

l. vln an ice cube making apparatus, an elongated ice cube forming tray of synthetic plastic material formed by molding as an integral unit and comprising a row of articulated ice forming receptacles of generally rectangular shape in plan in which the front and rear wall surfaces of the receptacles diverge upwardly from an inner bottom junction line thereby to form generally wedgeshaped, ice forming cavities in which the rear walls are flat, a rigid, dat, aluminum, ejector plate comprising an upper horizontal bar portion and a row of flat articulated blades depending therefrom having substantially the same coniiguration and dimensions as the inner surface of the rear walls of the receptacles, each of which blades extends into a receptacle with its bottom edge lying along said inner bottom junction line, support means for said tray including a longitudinal, at, rigid plate of high heat conductive material disposed at the same angle as the rear walls of said receptacles, said tray being mounted on said support means with the rear walls of its ice forming receptacles lying flat `against said rigid support plate, and means pivotally mounting said ejector plate on said support means in a manner to effect the pivoting thereof about a longitudinal axis coincident with the lower edges of said blades and said inner bottom junction line of the front and rear receptacle walls.

2. lee cube making apparatus as set forth in claim 1 in which the rigid rear support plate is provided with a short horizontal and rearwardly extending lip extending along the upper edge lthereof and in which said plastic tray is provided with a longitudinally extending, hookformed flange extending along the upper rear wall thereof adapted to receive said lip, thereby to provide a readily detachable means of securing the tray to the support.

3. lce cube making apparatus as set forth in claim 1 in which the ends of said upper bar portion of said ejector plate project beyond the ends of said tray and are rigidly attached to the upper free ends of a pair of pivoted arms, which arms are pivotally mounted at their lower ends on pivots mounted in said support member in axial alignment with said junction line of the inner front and rear wall surfaces of said receptacles.

4. Ice cube making apparatus including an elongated ice cube forming tray comprising a row of ice forming cavities of generally rectangular form in plan in which the front and rear walls of the cavities diverge upwardly from a longitudinal bottom line of junction and in which the rear walls are flat, a longitudinally arranged ejector plate having a continuous upper bar portion extending along and above said row of cavities and projecting slightly beyond said row of cavities at each end, said ejector plate including a row of articulated, downwardly extending, flat blades each entering a cavity and extending downward therein to the line of junction of said front and rear cavity walls, support means for said tray, means pivotally mounting said ejector plate in a manner to effect the pivoting thereof about the lower edges of said blades on a longitudinal axis coincident with said junction line of said cavity walls, said means comprising a pair of upright arms, one at each end of said tray, pivotally supported at their lower ends on pivots mounted on extensions of said suppotrt means which are in axial alignment with said cavity wall junction line, and said arms being rigidly attached at their upper ends to said projecting ends of said bar portion of said ejector plate, and means for oscillating said ejector plate including a driving motor, a crank driven by said motor, and a generally horizontal connecting rod pivotally connected at one end to said crank and at its other end to said bar portion of said ejector plate at an intermediate point along its length.

5. lce cube making apparatus as set forth in claim 4 in which the throw of said crank and the length of said connecting rod are such that said ejector plate is positioned flat against the rear wall of said cavity when said crank is in one dead center positioin.

6. ln a device of the class described, an elongated ice cube forming tray comprising a row of articulated ice forming receptacles of generally rectangular form in plan, in which the front and. rear walls diverge upwardly to form generally wedge-shaped, ice forming cavities, a longitudinally arranged ejector plate comprising a continuous portion overlying said tray and a row of depending articulated blades each entering a receptacle and extending to the bottom thereof, support means for said tray, and means pivotally mounting said ejector plate on said support means in a manner to cause said ejector plate to pivot about a longitudinal axis coincident with the lower edges of said ejector blades and the lower edges of said rear walls.

7. In a device of the class described, an elongated ice cube forming tray comprising a row of articulated ice forming receptacles of generally rectangular form in plan, in which the front and rear walls diverge upwardly from a junction line to form generally wedge-shaped, ice forming cavities, a longitudinally arranged ejector plate having a continuous upper portion overlying said tray and a row of depending articulated blades each entering a receptacle and extending downwardly to said junction line, support means for said tray, and means pivotally mounting said ejector plate on said support means in a member to cause said ejector plate to pivot about a longitudinal axis coincident with the lower edges of said ejector blades Vand said junction line.

8. Ajdevice as recited in claim 7 in which the tray is constructed of semi-rigid synthetic plastic material and in which said ejector plate is constructed of metal of high heat conductivity.

9. A device as recited in claim 7 in which the rear walls are fiat and in which the lower portionsy of the front walls are curved inwardly to said junction line.

l0. An ice' cube forming tray for use in automatic ice cube making apparatus constructed of synthetic plastic material, said tray including walls forming an ice forming cavity, an integrally formed hollow boss extending exteriorly from a lower portion of one of said cavity walls and including abottom wall separating the interior of said boss from said ice forming cavity, and a temperature sensitive switching device in said hollow boss including a bimetal disc having one tace thereof in contact with said bottom wall when in a higher than freezing temperature condition.

11. An ice cube forming tray as set forth in claim 10 in which said bimetal dise has an inwardly convex form Y at temperatures above freezing and snaps to an outwardly convex form in response to a predetermined decrease in temperature and in which said bottom wall of said hollow boss has a concave form corresponding to the inwardly convex form of said bimetal disc.

12. An ice cube forming tray as set forth in claim 10 in which the interior Walls of said hollow boss are cylindrical and in which said switching device further inciudes a disc-shaped, nonmetallic, electrical, resistance heater for resetting said bimetal disc to its higher than freezing temperature condition, and said disc-shaped heater being Vpositioned in said hollow boss and being spaced outwardly from and in close face-to-face relationship with said bimetal disc.

References Cited in the tile of this patent UNTED STATES PATENTS 

4. ICE CUBE MAKING APPARATUS INCLUDING AN ELONGATED ICE CUBE FORMING TRAY COMPRISING A ROW OF ICE FORMING CAVITIES OF GENERALLY RECTANGULAR FORM IN PLAN IN WHICH THE FRONT AND REAR WALLS OF THE CAVITIES DIVERGE UPWARDLY FROM A LONGITUDINAL BOTTOM LINE OF JUNCTION AND IN WHICH THE REAR WALLS ARE FLAT, A LONGITUDINALLY ARRANGED EJECTOR PLATE HAVING A CONTINUOUS UPPER BAR PORTION EXTENDING ALONG AND ABOVE SAID ROW OF CAVITIES AT EACH END, SAID SLIGHTLY BEYOND SAID ROW OF CAVITIES AND PROJECTING EJECTOR PLATE INCLUDING A ROW OF ARTICULATED, DOWNWARDLY EXTENDING, FLAT BLADES EACH ENTERING A CAVITY AND EXTENDING DOWNWARD THEREIN TO THE LINE OF JUNCTION OF SAID FRONT AND REAR CAVITY WALLS, SUPPORT MEANS FOR SAID TRAY, MEANS PIVOTALLY MOUNTING SAID EJECTOR PLATE IN A MANNER TO EFFECT THE PIVOTING THEREOF ABOUT THE LOWER EDGES OF SAID BLADES ON A LONGITUDINAL AXIS COINCIDENT WITH SAID JUNCTION LINE OF SAID CAVITY WALLS, SAID MEANS COMPRISING A PAIR OF UPRIGHT ARMS, ONE AT EACH END OF SAID TRAY, PIVOTALLY SUPPORTED AT THEIR LOWER ENDS ON PIVOTS MOUNTED ON EXTENSIONS OF SAID SUPPORT MEANS WHICH ARE IN AXIAL ALIGNMENT WITH SAID CAVITY WALL JUNCTION LINE, AND SAID ARMS BEING RIGIDLY ATTACHED AT THEIR UPPER ENDS TO SAID PROJECTING ENDS OF SAID BAR PORTION OF SAID EJECTOR PLATE, AND MEANS FOR OSCILLATING SAID EJECTOR PLATE INCLUDING A DRIVING MOTOR, A CRANK DRIVEN BY SAID MOTOR, AND A GENERALLY HORIZONTAL CONNECTING ROD PIVOTALLY CONNECTED AT ONE END TO SAID CRANK AND AT ITS OTHER END TO SAID BAR PORTION OF SAID EJECTOR PLATE AT AN INTERMEDIATE POINT ALONG ITS LENGTH. 